Target-Controlled Infusion of Propofol Induces Significant Hypertriglyceridemia in Healthy Dogs Undergoing Elective Orchiectomy

This study assessed serum triglyceride (TG) concentrations during target-controlled infusion (TCI) of propofol in healthy dogs undergoing elective orchiectomy and investigated the association between propofol infusion rate and serum TG concentrations. Eight male healthy dogs (14.8 ± 12.5 kg; median age 13.5 months; ASA I) were premedicated with acepromazine 0.05 mg/kg and morphine 0.4 mg/kg intramuscularly. Anesthesia was induced and maintained with propofol TCI targeting 7.0 µg/mL for 40 minutes. The primary outcome was serum TG concentration at four timepoints: TB (baseline), TIND (immediately after intubation), TINF20 (20 min), and TINF40 (40 min). Sample size was calculated a priori for 90% power. Statistical analysis was performed using the Friedman test followed by Dunn’s multiple-comparison test, with P < 0.05. All animals completed the protocol without adverse events. TG concentrations increased significantly from baseline [47 (30-73) mg/dL] to TIND [182 (100-227) mg/dL; P = 0.023], TINF20 [255 (132-733) mg/dL; P = 0.016], and TINF40 [293 (141-395) mg/dL; P = 0.008]. Hypertriglyceridemia (>112 mg/dL) occurred in 6/8 dogs (75.0%) after induction and 8/8 (100.0%) at 20 minutes. Infusion rate decreased 15.7% (0.51 ± 0.06 → 0.43 ± 0.03 mg/kg/min). No significant correlation was detected between propofol infusion rate and serum TG concentrations (r = 0.12; P = 0.54). However, the study is underpowered to evaluate potential associations, and further research is needed. Propofol TCI produces early and marked increases in triglyceride concentrations in healthy dogs even during short procedures. These findings suggest interindividual variability in triglyceride response, but causality cannot be inferred.